Security group G4S has announced that CEO Nick Buckles, who presided over the firm’s Olympic security shambles, is stepping down from his position at the end of May.

Buckles will be replaced by G4S’s current CFO Ashley Almanza, who only joined the company three weeks ago. Shares rose 3% following the announcement.

Buckles’ departure comes at the end of a turbulent 18 months for G4S. Last summer the group was excoriated for failing to provide enough security guards for the 2012 Olympic Games, a failure which forced the Government to draft in thousands of soldiers and policemen at the last minute.

Buckles was subsequently forced to appear before MPs and admit the episode was a “humiliating shambles.” for his company.